Osteosarcoma in dogs is highly malignant and generally has a poor prognosis, as it is difficult to treat with chemotherapeutic agents. However, it is believed that engaging in immune therapy can improve the dog’s condition, maintain quality of life (QOL), and help restore vitality and appetite. There are numerous cases where cancer in dogs has been controlled through immunity strategies using Cordy.

This page summarizes the causes, symptoms, treatment methods, and tips for improvement and recovery from osteosarcoma. Many improvement cases are also introduced. We hope it serves as a support and a ray of hope for everyone.

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About Osteosarcoma in Dogs

Osteosarcoma refers to a state in which tissues within the bone (such as bone marrow, periosteum, or cortical bone) become cancerous.
Osteosarcoma can occur in humans, but it is a particularly malignant tumor in dogs, especially large and giant breeds.

Osteosarcoma accounts for 85% of malignant tumors that occur in the skeletal system.
Since osteosarcoma arises from cancerous changes in bone tissue, veterinarians may explain it as “bone cancer.”

The metastasis rate is very high, and it is said that even with surgery, only about 10% of dogs live for more than a year.
In many cases, it is almost too late by the time it is discovered, and it is not uncommon to receive a prognosis of limited time remaining upon diagnosis.

Which Dogs Are Prone to Osteosarcoma?

Compared to small dogs, the incidence is higher in large and giant breeds, and the incidence rate of bone tumors in dogs weighing over 10 kg is said to be 150 times higher than in dogs under 10 kg.
It is also reported that males have a 20% higher incidence than females.

The peak age of onset is around 2 years old and 8 years old, creating a bimodal distribution. For large breeds, the tumors almost always occur in the limbs, whereas in small dogs, about 60% occur in the axial bones.

When it occurs in the limbs, it tends to appear ‘far from the elbow and close to the knee.’

Causes of Osteosarcoma in Dogs

Currently, the exact cause remains unclear.
However, as mentioned earlier, due to the difference in incidence rates based on body weight, it is almost certain that body size is involved.

In addition, it is speculated that factors such as fractures (foreign objects like metal plates used at fracture sites) may also play a role in canine osteosarcoma.

Symptoms of Osteosarcoma in Dogs

About 75% of osteosarcomas occur in the limbs. Specifically, the forelimbs have twice the incidence compared to the hindlimbs.
The remaining cases appear in axial skeleton bones such as the jaw, skull, and ribs.

The most common symptom of osteosarcoma is limping (lameness).
Other symptoms include a firm swelling at the affected part of the bone, and the dog showing aversion when that area is touched.
Due to the severe pain from the affected area, there can be a reduction in physical activity and a decrease in vitality and appetite.

Symptoms vary depending on the location of the osteosarcoma.
– Head: Facial deformity, respiratory symptoms such as snoring or nasal discharge, eye protrusion
– Spine: Paralysis, decreased motor function

Chronic lameness can lead to pathological fractures, suddenly worsening the lameness.

Metastasis of Osteosarcoma in Dogs

The most common site of metastasis for osteosarcoma is the lungs.
Even when it metastasizes to the lungs, it is considered a lung metastasis of osteosarcoma, not lung cancer, and retains the characteristics of osteosarcoma.

It can also metastasize to soft tissues and bones.

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Treatment of Osteosarcoma in Dogs

Osteosarcoma causes very severe pain, so pain management (とうつうかんり: treatment to stop pain) is the main focus. It is crucial to manage how much of the pain caused by osteosarcoma can be alleviated.

Surgery – Treatment of Osteosarcoma in Dogs

When osteosarcoma occurs, it results in very severe pain. Standard painkillers do not effectively relieve this cancerous pain.

The first choice treatment for osteosarcoma in the limbs is amputation. Amputation can relieve the pain.

In case of a forelimb, the amputation will be performed from the scapula, and in case of a hindlimb, it will be from the hip joint.

If the disease hasn’t progressed, a bone transplant surgery called “limb-sparing” can be performed, but due to a high rate of recurrence and complications, it is not often chosen.

Since surgery alone leaves a high possibility of metastasis, chemotherapy (anti-cancer drug treatment) is conducted as an adjuvant therapy, but even then, the cancer often recurs at a high rate.

Chemotherapy – Treatment of Osteosarcoma in Dogs

Chemotherapy refers to treatment with anti-cancer drugs. It is used for osteosarcoma located in areas with concentrated nerves or parts difficult to amputate, and when metastasis is detected through imaging diagnostics.
However, since osteosarcoma is resistant to anti-cancer drugs, it is essential to closely observe your dog’s condition to ensure that the treatment is effective and that your dog is not overly fatigued by side effects.

Anti-cancer drugs such as doxorubicin and carboplatin, or combination therapy with these two drugs, can be used. Recent reports also suggest that toceranib (Palladia), a molecular targeted therapy, can be effective.

If the side effects are severe and the treatment shows little efficacy, it is best to stop chemotherapy without hesitation and focus on restoring your dog’s strength as it could lead to a better prognosis.

If chemotherapy is recommended for your dog’s osteosarcoma treatment, consult thoroughly with your veterinarian to determine if it will indeed benefit your dog’s prognosis. Reading the following articles about anti-cancer drugs could be helpful to gain more understanding.

Anti-cancer Drug Related Articles

Radiation Therapy – Treatment of Osteosarcoma in Dogs

Radiation therapy may be combined with partial resection for osteosarcoma situated along the body axis.

While radiation therapy is excellent for local pain relief, it does not prevent metastasis to the lungs or other areas.
Additionally, due to radiation exposure concerns, the number of radiation sessions is limited.

If you decide to undergo radiation or chemotherapy, using Cordy for Immune Support and Placenta Extract Derived from Domestic SPF Pigs for Liver and Kidney Care can help manage side effects, potentially improving the quality of life (QOL).

Prevention of Osteosarcoma in Dogs

Unfortunately, there are no means of preventing it.
Early detection and early treatment can significantly affect the prognosis.
Regularly check your pet’s body and watch for any abnormalities in their gait.

Try Cordy to Improve the Prognosis of Osteosarcoma

For osteosarcoma, amputation is the first option for limbs, and complete or partial resection for the trunk. However, due to age or health condition, surgery may not always be feasible.

Even if surgery is successful or chemotherapy is administered, cases where osteosarcoma progression cannot be controlled are not uncommon.

Although osteosarcoma is hard to treat, the Cordy Laboratory is researching how Cordy works on the immune system.
While the response can vary, there is a sufficient possibility of regaining appetite and vigor.


Our laboratory is researching whether Cordy can modulate the immune system and potentially have effects on cancer.

If you have any questions, please contact us.

監修獣医師:林美彩  所属クリニック:chicoどうぶつ診療所

林美彩

代替療法と西洋医学、両方の動物病院での勤務経験と多数のコルディの臨床経験をもつ。 モノリス在籍時には、一般的な動物医療(西洋医学)だけでは対応が困難な症例に対して多くの相談を受け、免疫の大切さを痛烈に実感する。
ペットたちの健康維持・改善のためには薬に頼った対処療法だけではなく、「普段の生活環境や食事を見直し、自宅でさまざまなケアを取り入れることで免疫力を維持し、病気にならない体づくりを目指していくことが大切である」という考えを提唱し普及活動に従事している。

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